Technical Abstract:
A one-parameter model for soil hydraulic properties is based on a strong relationship observed between intercept and slope of a log-log plot of soil-water pressure head and soil water content or unsaturated hydraulic conductivity. Further more, for widely different soils this relationship is found to coalesce into one common relationship. These characteristics allow representation of the soil hydraulic properties by Brook-Corey type functions with only one unknown parameter, the slope of the log-log plot. Thus, the soil water retention curve and unsaturated conductivity functions for a variety of soils can be scaled based on their known slope values, or of 33-kPa water content from which the slope can be obtained. We show the results of scaling hydraulic properties based on this technique within several soil types as well as across soil types.